In the prior art, niobium cavities are the building blocks of particle accelerators, free electron laser and the like apparatus and are well known and commonly used in the operation of such devices. Such niobium cavities are fabricated from high purity niobium sheet or cast plate, via deep drawing, e-beam welding and chemical surface cleaning to obtain high accelerating gradients and quality factors. Often the quality factors at high gradients degrade over time for cavities produced by these methods. Such degradation appears to be affected by adherent surface oxide layers, trapped hydrogen and/or interactions between interstitial oxygen and hydrogen in the niobium material. The release of oxygen, hydrogen or the reaction products of these materials results in degradation of the vacuum within the niobium cavities thereby negatively affecting the quality of the output of such cavities.
There therefore exists a need for niobium cavity that does not exhibit the negative effects caused by the release of such gases or gaseous products under ultra high vacuum conditions.